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1// SPDX-License-Identifier: GPL-2.0+
2/*
3 * Based on drivers/serial/8250.c by Russell King.
4 *
5 * Author: Nicolas Pitre
6 * Created: Feb 20, 2003
7 * Copyright: (C) 2003 Monta Vista Software, Inc.
8 *
9 * Note 1: This driver is made separate from the already too overloaded
10 * 8250.c because it needs some kirks of its own and that'll make it
11 * easier to add DMA support.
12 *
13 * Note 2: I'm too sick of device allocation policies for serial ports.
14 * If someone else wants to request an "official" allocation of major/minor
15 * for this driver please be my guest. And don't forget that new hardware
16 * to come from Intel might have more than 3 or 4 of those UARTs. Let's
17 * hope for a better port registration and dynamic device allocation scheme
18 * with the serial core maintainer satisfaction to appear soon.
19 */
20
21
22#include <linux/ioport.h>
23#include <linux/init.h>
24#include <linux/console.h>
25#include <linux/sysrq.h>
26#include <linux/serial.h>
27#include <linux/serial_reg.h>
28#include <linux/circ_buf.h>
29#include <linux/delay.h>
30#include <linux/interrupt.h>
31#include <linux/of.h>
32#include <linux/platform_device.h>
33#include <linux/tty.h>
34#include <linux/tty_flip.h>
35#include <linux/serial_core.h>
36#include <linux/clk.h>
37#include <linux/io.h>
38#include <linux/slab.h>
39
40#define PXA_NAME_LEN 8
41
42struct uart_pxa_port {
43 struct uart_port port;
44 unsigned char ier;
45 unsigned char lcr;
46 unsigned char mcr;
47 unsigned int lsr_break_flag;
48 struct clk *clk;
49 char name[PXA_NAME_LEN];
50};
51
52static inline unsigned int serial_in(struct uart_pxa_port *up, int offset)
53{
54 offset <<= 2;
55 return readl(up->port.membase + offset);
56}
57
58static inline void serial_out(struct uart_pxa_port *up, int offset, int value)
59{
60 offset <<= 2;
61 writel(value, up->port.membase + offset);
62}
63
64static void serial_pxa_enable_ms(struct uart_port *port)
65{
66 struct uart_pxa_port *up = (struct uart_pxa_port *)port;
67
68 up->ier |= UART_IER_MSI;
69 serial_out(up, UART_IER, up->ier);
70}
71
72static void serial_pxa_stop_tx(struct uart_port *port)
73{
74 struct uart_pxa_port *up = (struct uart_pxa_port *)port;
75
76 if (up->ier & UART_IER_THRI) {
77 up->ier &= ~UART_IER_THRI;
78 serial_out(up, UART_IER, up->ier);
79 }
80}
81
82static void serial_pxa_stop_rx(struct uart_port *port)
83{
84 struct uart_pxa_port *up = (struct uart_pxa_port *)port;
85
86 up->ier &= ~UART_IER_RLSI;
87 up->port.read_status_mask &= ~UART_LSR_DR;
88 serial_out(up, UART_IER, up->ier);
89}
90
91static inline void receive_chars(struct uart_pxa_port *up, int *status)
92{
93 u8 ch, flag;
94 int max_count = 256;
95
96 do {
97 /* work around Errata #20 according to
98 * Intel(R) PXA27x Processor Family
99 * Specification Update (May 2005)
100 *
101 * Step 2
102 * Disable the Reciever Time Out Interrupt via IER[RTOEI]
103 */
104 up->ier &= ~UART_IER_RTOIE;
105 serial_out(up, UART_IER, up->ier);
106
107 ch = serial_in(up, UART_RX);
108 flag = TTY_NORMAL;
109 up->port.icount.rx++;
110
111 if (unlikely(*status & (UART_LSR_BI | UART_LSR_PE |
112 UART_LSR_FE | UART_LSR_OE))) {
113 /*
114 * For statistics only
115 */
116 if (*status & UART_LSR_BI) {
117 *status &= ~(UART_LSR_FE | UART_LSR_PE);
118 up->port.icount.brk++;
119 /*
120 * We do the SysRQ and SAK checking
121 * here because otherwise the break
122 * may get masked by ignore_status_mask
123 * or read_status_mask.
124 */
125 if (uart_handle_break(&up->port))
126 goto ignore_char;
127 } else if (*status & UART_LSR_PE)
128 up->port.icount.parity++;
129 else if (*status & UART_LSR_FE)
130 up->port.icount.frame++;
131 if (*status & UART_LSR_OE)
132 up->port.icount.overrun++;
133
134 /*
135 * Mask off conditions which should be ignored.
136 */
137 *status &= up->port.read_status_mask;
138
139#ifdef CONFIG_SERIAL_PXA_CONSOLE
140 if (up->port.line == up->port.cons->index) {
141 /* Recover the break flag from console xmit */
142 *status |= up->lsr_break_flag;
143 up->lsr_break_flag = 0;
144 }
145#endif
146 if (*status & UART_LSR_BI) {
147 flag = TTY_BREAK;
148 } else if (*status & UART_LSR_PE)
149 flag = TTY_PARITY;
150 else if (*status & UART_LSR_FE)
151 flag = TTY_FRAME;
152 }
153
154 if (uart_handle_sysrq_char(&up->port, ch))
155 goto ignore_char;
156
157 uart_insert_char(&up->port, *status, UART_LSR_OE, ch, flag);
158
159 ignore_char:
160 *status = serial_in(up, UART_LSR);
161 } while ((*status & UART_LSR_DR) && (max_count-- > 0));
162 tty_flip_buffer_push(&up->port.state->port);
163
164 /* work around Errata #20 according to
165 * Intel(R) PXA27x Processor Family
166 * Specification Update (May 2005)
167 *
168 * Step 6:
169 * No more data in FIFO: Re-enable RTO interrupt via IER[RTOIE]
170 */
171 up->ier |= UART_IER_RTOIE;
172 serial_out(up, UART_IER, up->ier);
173}
174
175static void transmit_chars(struct uart_pxa_port *up)
176{
177 u8 ch;
178
179 uart_port_tx_limited(&up->port, ch, up->port.fifosize / 2,
180 true,
181 serial_out(up, UART_TX, ch),
182 ({}));
183}
184
185static void serial_pxa_start_tx(struct uart_port *port)
186{
187 struct uart_pxa_port *up = (struct uart_pxa_port *)port;
188
189 if (!(up->ier & UART_IER_THRI)) {
190 up->ier |= UART_IER_THRI;
191 serial_out(up, UART_IER, up->ier);
192 }
193}
194
195/* should hold up->port.lock */
196static inline void check_modem_status(struct uart_pxa_port *up)
197{
198 int status;
199
200 status = serial_in(up, UART_MSR);
201
202 if ((status & UART_MSR_ANY_DELTA) == 0)
203 return;
204
205 if (status & UART_MSR_TERI)
206 up->port.icount.rng++;
207 if (status & UART_MSR_DDSR)
208 up->port.icount.dsr++;
209 if (status & UART_MSR_DDCD)
210 uart_handle_dcd_change(&up->port, status & UART_MSR_DCD);
211 if (status & UART_MSR_DCTS)
212 uart_handle_cts_change(&up->port, status & UART_MSR_CTS);
213
214 wake_up_interruptible(&up->port.state->port.delta_msr_wait);
215}
216
217/*
218 * This handles the interrupt from one port.
219 */
220static inline irqreturn_t serial_pxa_irq(int irq, void *dev_id)
221{
222 struct uart_pxa_port *up = dev_id;
223 unsigned int iir, lsr;
224
225 iir = serial_in(up, UART_IIR);
226 if (iir & UART_IIR_NO_INT)
227 return IRQ_NONE;
228 uart_port_lock(&up->port);
229 lsr = serial_in(up, UART_LSR);
230 if (lsr & UART_LSR_DR)
231 receive_chars(up, &lsr);
232 check_modem_status(up);
233 if (lsr & UART_LSR_THRE)
234 transmit_chars(up);
235 uart_port_unlock(&up->port);
236 return IRQ_HANDLED;
237}
238
239static unsigned int serial_pxa_tx_empty(struct uart_port *port)
240{
241 struct uart_pxa_port *up = (struct uart_pxa_port *)port;
242 unsigned long flags;
243 unsigned int ret;
244
245 uart_port_lock_irqsave(&up->port, &flags);
246 ret = serial_in(up, UART_LSR) & UART_LSR_TEMT ? TIOCSER_TEMT : 0;
247 uart_port_unlock_irqrestore(&up->port, flags);
248
249 return ret;
250}
251
252static unsigned int serial_pxa_get_mctrl(struct uart_port *port)
253{
254 struct uart_pxa_port *up = (struct uart_pxa_port *)port;
255 unsigned char status;
256 unsigned int ret;
257
258 status = serial_in(up, UART_MSR);
259
260 ret = 0;
261 if (status & UART_MSR_DCD)
262 ret |= TIOCM_CAR;
263 if (status & UART_MSR_RI)
264 ret |= TIOCM_RNG;
265 if (status & UART_MSR_DSR)
266 ret |= TIOCM_DSR;
267 if (status & UART_MSR_CTS)
268 ret |= TIOCM_CTS;
269 return ret;
270}
271
272static void serial_pxa_set_mctrl(struct uart_port *port, unsigned int mctrl)
273{
274 struct uart_pxa_port *up = (struct uart_pxa_port *)port;
275 unsigned char mcr = 0;
276
277 if (mctrl & TIOCM_RTS)
278 mcr |= UART_MCR_RTS;
279 if (mctrl & TIOCM_DTR)
280 mcr |= UART_MCR_DTR;
281 if (mctrl & TIOCM_OUT1)
282 mcr |= UART_MCR_OUT1;
283 if (mctrl & TIOCM_OUT2)
284 mcr |= UART_MCR_OUT2;
285 if (mctrl & TIOCM_LOOP)
286 mcr |= UART_MCR_LOOP;
287
288 mcr |= up->mcr;
289
290 serial_out(up, UART_MCR, mcr);
291}
292
293static void serial_pxa_break_ctl(struct uart_port *port, int break_state)
294{
295 struct uart_pxa_port *up = (struct uart_pxa_port *)port;
296 unsigned long flags;
297
298 uart_port_lock_irqsave(&up->port, &flags);
299 if (break_state == -1)
300 up->lcr |= UART_LCR_SBC;
301 else
302 up->lcr &= ~UART_LCR_SBC;
303 serial_out(up, UART_LCR, up->lcr);
304 uart_port_unlock_irqrestore(&up->port, flags);
305}
306
307static int serial_pxa_startup(struct uart_port *port)
308{
309 struct uart_pxa_port *up = (struct uart_pxa_port *)port;
310 unsigned long flags;
311 int retval;
312
313 if (port->line == 3) /* HWUART */
314 up->mcr |= UART_MCR_AFE;
315 else
316 up->mcr = 0;
317
318 up->port.uartclk = clk_get_rate(up->clk);
319
320 /*
321 * Allocate the IRQ
322 */
323 retval = request_irq(up->port.irq, serial_pxa_irq, 0, up->name, up);
324 if (retval)
325 return retval;
326
327 /*
328 * Clear the FIFO buffers and disable them.
329 * (they will be reenabled in set_termios())
330 */
331 serial_out(up, UART_FCR, UART_FCR_ENABLE_FIFO);
332 serial_out(up, UART_FCR, UART_FCR_ENABLE_FIFO |
333 UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT);
334 serial_out(up, UART_FCR, 0);
335
336 /*
337 * Clear the interrupt registers.
338 */
339 (void) serial_in(up, UART_LSR);
340 (void) serial_in(up, UART_RX);
341 (void) serial_in(up, UART_IIR);
342 (void) serial_in(up, UART_MSR);
343
344 /*
345 * Now, initialize the UART
346 */
347 serial_out(up, UART_LCR, UART_LCR_WLEN8);
348
349 uart_port_lock_irqsave(&up->port, &flags);
350 up->port.mctrl |= TIOCM_OUT2;
351 serial_pxa_set_mctrl(&up->port, up->port.mctrl);
352 uart_port_unlock_irqrestore(&up->port, flags);
353
354 /*
355 * Finally, enable interrupts. Note: Modem status interrupts
356 * are set via set_termios(), which will be occurring imminently
357 * anyway, so we don't enable them here.
358 */
359 up->ier = UART_IER_RLSI | UART_IER_RDI | UART_IER_RTOIE | UART_IER_UUE;
360 serial_out(up, UART_IER, up->ier);
361
362 /*
363 * And clear the interrupt registers again for luck.
364 */
365 (void) serial_in(up, UART_LSR);
366 (void) serial_in(up, UART_RX);
367 (void) serial_in(up, UART_IIR);
368 (void) serial_in(up, UART_MSR);
369
370 return 0;
371}
372
373static void serial_pxa_shutdown(struct uart_port *port)
374{
375 struct uart_pxa_port *up = (struct uart_pxa_port *)port;
376 unsigned long flags;
377
378 free_irq(up->port.irq, up);
379
380 /*
381 * Disable interrupts from this port
382 */
383 up->ier = 0;
384 serial_out(up, UART_IER, 0);
385
386 uart_port_lock_irqsave(&up->port, &flags);
387 up->port.mctrl &= ~TIOCM_OUT2;
388 serial_pxa_set_mctrl(&up->port, up->port.mctrl);
389 uart_port_unlock_irqrestore(&up->port, flags);
390
391 /*
392 * Disable break condition and FIFOs
393 */
394 serial_out(up, UART_LCR, serial_in(up, UART_LCR) & ~UART_LCR_SBC);
395 serial_out(up, UART_FCR, UART_FCR_ENABLE_FIFO |
396 UART_FCR_CLEAR_RCVR |
397 UART_FCR_CLEAR_XMIT);
398 serial_out(up, UART_FCR, 0);
399}
400
401static void
402serial_pxa_set_termios(struct uart_port *port, struct ktermios *termios,
403 const struct ktermios *old)
404{
405 struct uart_pxa_port *up = (struct uart_pxa_port *)port;
406 unsigned char cval, fcr = 0;
407 unsigned long flags;
408 unsigned int baud, quot;
409 unsigned int dll;
410
411 cval = UART_LCR_WLEN(tty_get_char_size(termios->c_cflag));
412
413 if (termios->c_cflag & CSTOPB)
414 cval |= UART_LCR_STOP;
415 if (termios->c_cflag & PARENB)
416 cval |= UART_LCR_PARITY;
417 if (!(termios->c_cflag & PARODD))
418 cval |= UART_LCR_EPAR;
419
420 /*
421 * Ask the core to calculate the divisor for us.
422 */
423 baud = uart_get_baud_rate(port, termios, old, 0, port->uartclk/16);
424 quot = uart_get_divisor(port, baud);
425
426 if ((up->port.uartclk / quot) < (2400 * 16))
427 fcr = UART_FCR_ENABLE_FIFO | UART_FCR_PXAR1;
428 else if ((up->port.uartclk / quot) < (230400 * 16))
429 fcr = UART_FCR_ENABLE_FIFO | UART_FCR_PXAR8;
430 else
431 fcr = UART_FCR_ENABLE_FIFO | UART_FCR_PXAR32;
432
433 /*
434 * Ok, we're now changing the port state. Do it with
435 * interrupts disabled.
436 */
437 uart_port_lock_irqsave(&up->port, &flags);
438
439 /*
440 * Ensure the port will be enabled.
441 * This is required especially for serial console.
442 */
443 up->ier |= UART_IER_UUE;
444
445 /*
446 * Update the per-port timeout.
447 */
448 uart_update_timeout(port, termios->c_cflag, baud);
449
450 up->port.read_status_mask = UART_LSR_OE | UART_LSR_THRE | UART_LSR_DR;
451 if (termios->c_iflag & INPCK)
452 up->port.read_status_mask |= UART_LSR_FE | UART_LSR_PE;
453 if (termios->c_iflag & (IGNBRK | BRKINT | PARMRK))
454 up->port.read_status_mask |= UART_LSR_BI;
455
456 /*
457 * Characters to ignore
458 */
459 up->port.ignore_status_mask = 0;
460 if (termios->c_iflag & IGNPAR)
461 up->port.ignore_status_mask |= UART_LSR_PE | UART_LSR_FE;
462 if (termios->c_iflag & IGNBRK) {
463 up->port.ignore_status_mask |= UART_LSR_BI;
464 /*
465 * If we're ignoring parity and break indicators,
466 * ignore overruns too (for real raw support).
467 */
468 if (termios->c_iflag & IGNPAR)
469 up->port.ignore_status_mask |= UART_LSR_OE;
470 }
471
472 /*
473 * ignore all characters if CREAD is not set
474 */
475 if ((termios->c_cflag & CREAD) == 0)
476 up->port.ignore_status_mask |= UART_LSR_DR;
477
478 /*
479 * CTS flow control flag and modem status interrupts
480 */
481 up->ier &= ~UART_IER_MSI;
482 if (UART_ENABLE_MS(&up->port, termios->c_cflag))
483 up->ier |= UART_IER_MSI;
484
485 serial_out(up, UART_IER, up->ier);
486
487 if (termios->c_cflag & CRTSCTS)
488 up->mcr |= UART_MCR_AFE;
489 else
490 up->mcr &= ~UART_MCR_AFE;
491
492 serial_out(up, UART_LCR, cval | UART_LCR_DLAB); /* set DLAB */
493 serial_out(up, UART_DLL, quot & 0xff); /* LS of divisor */
494
495 /*
496 * work around Errata #75 according to Intel(R) PXA27x Processor Family
497 * Specification Update (Nov 2005)
498 */
499 dll = serial_in(up, UART_DLL);
500 WARN_ON(dll != (quot & 0xff));
501
502 serial_out(up, UART_DLM, quot >> 8); /* MS of divisor */
503 serial_out(up, UART_LCR, cval); /* reset DLAB */
504 up->lcr = cval; /* Save LCR */
505 serial_pxa_set_mctrl(&up->port, up->port.mctrl);
506 serial_out(up, UART_FCR, fcr);
507 uart_port_unlock_irqrestore(&up->port, flags);
508}
509
510static void
511serial_pxa_pm(struct uart_port *port, unsigned int state,
512 unsigned int oldstate)
513{
514 struct uart_pxa_port *up = (struct uart_pxa_port *)port;
515
516 if (!state)
517 clk_prepare_enable(up->clk);
518 else
519 clk_disable_unprepare(up->clk);
520}
521
522static void serial_pxa_release_port(struct uart_port *port)
523{
524}
525
526static int serial_pxa_request_port(struct uart_port *port)
527{
528 return 0;
529}
530
531static void serial_pxa_config_port(struct uart_port *port, int flags)
532{
533 struct uart_pxa_port *up = (struct uart_pxa_port *)port;
534 up->port.type = PORT_PXA;
535}
536
537static int
538serial_pxa_verify_port(struct uart_port *port, struct serial_struct *ser)
539{
540 /* we don't want the core code to modify any port params */
541 return -EINVAL;
542}
543
544static const char *
545serial_pxa_type(struct uart_port *port)
546{
547 struct uart_pxa_port *up = (struct uart_pxa_port *)port;
548 return up->name;
549}
550
551static struct uart_pxa_port *serial_pxa_ports[4];
552static struct uart_driver serial_pxa_reg;
553
554#ifdef CONFIG_SERIAL_PXA_CONSOLE
555
556/*
557 * Wait for transmitter & holding register to empty
558 */
559static void wait_for_xmitr(struct uart_pxa_port *up)
560{
561 unsigned int status, tmout = 10000;
562
563 /* Wait up to 10ms for the character(s) to be sent. */
564 do {
565 status = serial_in(up, UART_LSR);
566
567 if (status & UART_LSR_BI)
568 up->lsr_break_flag = UART_LSR_BI;
569
570 if (--tmout == 0)
571 break;
572 udelay(1);
573 } while (!uart_lsr_tx_empty(status));
574
575 /* Wait up to 1s for flow control if necessary */
576 if (up->port.flags & UPF_CONS_FLOW) {
577 tmout = 1000000;
578 while (--tmout &&
579 ((serial_in(up, UART_MSR) & UART_MSR_CTS) == 0))
580 udelay(1);
581 }
582}
583
584static void serial_pxa_console_putchar(struct uart_port *port, unsigned char ch)
585{
586 struct uart_pxa_port *up = (struct uart_pxa_port *)port;
587
588 wait_for_xmitr(up);
589 serial_out(up, UART_TX, ch);
590}
591
592/*
593 * Print a string to the serial port trying not to disturb
594 * any possible real use of the port...
595 *
596 * The console_lock must be held when we get here.
597 */
598static void
599serial_pxa_console_write(struct console *co, const char *s, unsigned int count)
600{
601 struct uart_pxa_port *up = serial_pxa_ports[co->index];
602 unsigned int ier;
603 unsigned long flags;
604 int locked = 1;
605
606 clk_enable(up->clk);
607 local_irq_save(flags);
608 if (up->port.sysrq)
609 locked = 0;
610 else if (oops_in_progress)
611 locked = uart_port_trylock(&up->port);
612 else
613 uart_port_lock(&up->port);
614
615 /*
616 * First save the IER then disable the interrupts
617 */
618 ier = serial_in(up, UART_IER);
619 serial_out(up, UART_IER, UART_IER_UUE);
620
621 uart_console_write(&up->port, s, count, serial_pxa_console_putchar);
622
623 /*
624 * Finally, wait for transmitter to become empty
625 * and restore the IER
626 */
627 wait_for_xmitr(up);
628 serial_out(up, UART_IER, ier);
629
630 if (locked)
631 uart_port_unlock(&up->port);
632 local_irq_restore(flags);
633 clk_disable(up->clk);
634
635}
636
637#ifdef CONFIG_CONSOLE_POLL
638/*
639 * Console polling routines for writing and reading from the uart while
640 * in an interrupt or debug context.
641 */
642
643static int serial_pxa_get_poll_char(struct uart_port *port)
644{
645 struct uart_pxa_port *up = (struct uart_pxa_port *)port;
646 unsigned char lsr = serial_in(up, UART_LSR);
647
648 while (!(lsr & UART_LSR_DR))
649 lsr = serial_in(up, UART_LSR);
650
651 return serial_in(up, UART_RX);
652}
653
654
655static void serial_pxa_put_poll_char(struct uart_port *port,
656 unsigned char c)
657{
658 unsigned int ier;
659 struct uart_pxa_port *up = (struct uart_pxa_port *)port;
660
661 /*
662 * First save the IER then disable the interrupts
663 */
664 ier = serial_in(up, UART_IER);
665 serial_out(up, UART_IER, UART_IER_UUE);
666
667 wait_for_xmitr(up);
668 /*
669 * Send the character out.
670 */
671 serial_out(up, UART_TX, c);
672
673 /*
674 * Finally, wait for transmitter to become empty
675 * and restore the IER
676 */
677 wait_for_xmitr(up);
678 serial_out(up, UART_IER, ier);
679}
680
681#endif /* CONFIG_CONSOLE_POLL */
682
683static int __init
684serial_pxa_console_setup(struct console *co, char *options)
685{
686 struct uart_pxa_port *up;
687 int baud = 9600;
688 int bits = 8;
689 int parity = 'n';
690 int flow = 'n';
691
692 if (co->index == -1 || co->index >= serial_pxa_reg.nr)
693 co->index = 0;
694 up = serial_pxa_ports[co->index];
695 if (!up)
696 return -ENODEV;
697
698 if (options)
699 uart_parse_options(options, &baud, &parity, &bits, &flow);
700
701 return uart_set_options(&up->port, co, baud, parity, bits, flow);
702}
703
704static struct console serial_pxa_console = {
705 .name = "ttyS",
706 .write = serial_pxa_console_write,
707 .device = uart_console_device,
708 .setup = serial_pxa_console_setup,
709 .flags = CON_PRINTBUFFER,
710 .index = -1,
711 .data = &serial_pxa_reg,
712};
713
714#define PXA_CONSOLE &serial_pxa_console
715#else
716#define PXA_CONSOLE NULL
717#endif
718
719static const struct uart_ops serial_pxa_pops = {
720 .tx_empty = serial_pxa_tx_empty,
721 .set_mctrl = serial_pxa_set_mctrl,
722 .get_mctrl = serial_pxa_get_mctrl,
723 .stop_tx = serial_pxa_stop_tx,
724 .start_tx = serial_pxa_start_tx,
725 .stop_rx = serial_pxa_stop_rx,
726 .enable_ms = serial_pxa_enable_ms,
727 .break_ctl = serial_pxa_break_ctl,
728 .startup = serial_pxa_startup,
729 .shutdown = serial_pxa_shutdown,
730 .set_termios = serial_pxa_set_termios,
731 .pm = serial_pxa_pm,
732 .type = serial_pxa_type,
733 .release_port = serial_pxa_release_port,
734 .request_port = serial_pxa_request_port,
735 .config_port = serial_pxa_config_port,
736 .verify_port = serial_pxa_verify_port,
737#if defined(CONFIG_CONSOLE_POLL) && defined(CONFIG_SERIAL_PXA_CONSOLE)
738 .poll_get_char = serial_pxa_get_poll_char,
739 .poll_put_char = serial_pxa_put_poll_char,
740#endif
741};
742
743static struct uart_driver serial_pxa_reg = {
744 .owner = THIS_MODULE,
745 .driver_name = "PXA serial",
746 .dev_name = "ttyS",
747 .major = TTY_MAJOR,
748 .minor = 64,
749 .nr = 4,
750 .cons = PXA_CONSOLE,
751};
752
753#ifdef CONFIG_PM
754static int serial_pxa_suspend(struct device *dev)
755{
756 struct uart_pxa_port *sport = dev_get_drvdata(dev);
757
758 if (sport)
759 uart_suspend_port(&serial_pxa_reg, &sport->port);
760
761 return 0;
762}
763
764static int serial_pxa_resume(struct device *dev)
765{
766 struct uart_pxa_port *sport = dev_get_drvdata(dev);
767
768 if (sport)
769 uart_resume_port(&serial_pxa_reg, &sport->port);
770
771 return 0;
772}
773
774static const struct dev_pm_ops serial_pxa_pm_ops = {
775 .suspend = serial_pxa_suspend,
776 .resume = serial_pxa_resume,
777};
778#endif
779
780static const struct of_device_id serial_pxa_dt_ids[] = {
781 { .compatible = "mrvl,pxa-uart", },
782 { .compatible = "mrvl,mmp-uart", },
783 {}
784};
785
786static int serial_pxa_probe_dt(struct platform_device *pdev,
787 struct uart_pxa_port *sport)
788{
789 struct device_node *np = pdev->dev.of_node;
790 int ret;
791
792 if (!np)
793 return 1;
794
795 ret = of_alias_get_id(np, "serial");
796 if (ret < 0) {
797 dev_err(&pdev->dev, "failed to get alias id, errno %d\n", ret);
798 return ret;
799 }
800 sport->port.line = ret;
801 return 0;
802}
803
804static int serial_pxa_probe(struct platform_device *dev)
805{
806 struct uart_pxa_port *sport;
807 struct resource *mmres;
808 int ret;
809 int irq;
810
811 mmres = platform_get_resource(dev, IORESOURCE_MEM, 0);
812 if (!mmres)
813 return -ENODEV;
814
815 irq = platform_get_irq(dev, 0);
816 if (irq < 0)
817 return irq;
818
819 sport = kzalloc(sizeof(struct uart_pxa_port), GFP_KERNEL);
820 if (!sport)
821 return -ENOMEM;
822
823 sport->clk = clk_get(&dev->dev, NULL);
824 if (IS_ERR(sport->clk)) {
825 ret = PTR_ERR(sport->clk);
826 goto err_free;
827 }
828
829 ret = clk_prepare(sport->clk);
830 if (ret) {
831 clk_put(sport->clk);
832 goto err_free;
833 }
834
835 sport->port.type = PORT_PXA;
836 sport->port.iotype = UPIO_MEM;
837 sport->port.mapbase = mmres->start;
838 sport->port.irq = irq;
839 sport->port.fifosize = 64;
840 sport->port.ops = &serial_pxa_pops;
841 sport->port.dev = &dev->dev;
842 sport->port.flags = UPF_IOREMAP | UPF_BOOT_AUTOCONF;
843 sport->port.uartclk = clk_get_rate(sport->clk);
844 sport->port.has_sysrq = IS_ENABLED(CONFIG_SERIAL_PXA_CONSOLE);
845
846 ret = serial_pxa_probe_dt(dev, sport);
847 if (ret > 0)
848 sport->port.line = dev->id;
849 else if (ret < 0)
850 goto err_clk;
851 if (sport->port.line >= ARRAY_SIZE(serial_pxa_ports)) {
852 dev_err(&dev->dev, "serial%d out of range\n", sport->port.line);
853 ret = -EINVAL;
854 goto err_clk;
855 }
856 snprintf(sport->name, PXA_NAME_LEN - 1, "UART%d", sport->port.line + 1);
857
858 sport->port.membase = ioremap(mmres->start, resource_size(mmres));
859 if (!sport->port.membase) {
860 ret = -ENOMEM;
861 goto err_clk;
862 }
863
864 serial_pxa_ports[sport->port.line] = sport;
865
866 uart_add_one_port(&serial_pxa_reg, &sport->port);
867 platform_set_drvdata(dev, sport);
868
869 return 0;
870
871 err_clk:
872 clk_unprepare(sport->clk);
873 clk_put(sport->clk);
874 err_free:
875 kfree(sport);
876 return ret;
877}
878
879static struct platform_driver serial_pxa_driver = {
880 .probe = serial_pxa_probe,
881
882 .driver = {
883 .name = "pxa2xx-uart",
884#ifdef CONFIG_PM
885 .pm = &serial_pxa_pm_ops,
886#endif
887 .suppress_bind_attrs = true,
888 .of_match_table = serial_pxa_dt_ids,
889 },
890};
891
892
893/* 8250 driver for PXA serial ports should be used */
894static int __init serial_pxa_init(void)
895{
896 int ret;
897
898 ret = uart_register_driver(&serial_pxa_reg);
899 if (ret != 0)
900 return ret;
901
902 ret = platform_driver_register(&serial_pxa_driver);
903 if (ret != 0)
904 uart_unregister_driver(&serial_pxa_reg);
905
906 return ret;
907}
908device_initcall(serial_pxa_init);
1/*
2 * Based on drivers/serial/8250.c by Russell King.
3 *
4 * Author: Nicolas Pitre
5 * Created: Feb 20, 2003
6 * Copyright: (C) 2003 Monta Vista Software, Inc.
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 2 of the License, or
11 * (at your option) any later version.
12 *
13 * Note 1: This driver is made separate from the already too overloaded
14 * 8250.c because it needs some kirks of its own and that'll make it
15 * easier to add DMA support.
16 *
17 * Note 2: I'm too sick of device allocation policies for serial ports.
18 * If someone else wants to request an "official" allocation of major/minor
19 * for this driver please be my guest. And don't forget that new hardware
20 * to come from Intel might have more than 3 or 4 of those UARTs. Let's
21 * hope for a better port registration and dynamic device allocation scheme
22 * with the serial core maintainer satisfaction to appear soon.
23 */
24
25
26#if defined(CONFIG_SERIAL_PXA_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
27#define SUPPORT_SYSRQ
28#endif
29
30#include <linux/module.h>
31#include <linux/ioport.h>
32#include <linux/init.h>
33#include <linux/console.h>
34#include <linux/sysrq.h>
35#include <linux/serial_reg.h>
36#include <linux/circ_buf.h>
37#include <linux/delay.h>
38#include <linux/interrupt.h>
39#include <linux/of.h>
40#include <linux/platform_device.h>
41#include <linux/tty.h>
42#include <linux/tty_flip.h>
43#include <linux/serial_core.h>
44#include <linux/clk.h>
45#include <linux/io.h>
46#include <linux/slab.h>
47
48#define PXA_NAME_LEN 8
49
50struct uart_pxa_port {
51 struct uart_port port;
52 unsigned char ier;
53 unsigned char lcr;
54 unsigned char mcr;
55 unsigned int lsr_break_flag;
56 struct clk *clk;
57 char name[PXA_NAME_LEN];
58};
59
60static inline unsigned int serial_in(struct uart_pxa_port *up, int offset)
61{
62 offset <<= 2;
63 return readl(up->port.membase + offset);
64}
65
66static inline void serial_out(struct uart_pxa_port *up, int offset, int value)
67{
68 offset <<= 2;
69 writel(value, up->port.membase + offset);
70}
71
72static void serial_pxa_enable_ms(struct uart_port *port)
73{
74 struct uart_pxa_port *up = (struct uart_pxa_port *)port;
75
76 up->ier |= UART_IER_MSI;
77 serial_out(up, UART_IER, up->ier);
78}
79
80static void serial_pxa_stop_tx(struct uart_port *port)
81{
82 struct uart_pxa_port *up = (struct uart_pxa_port *)port;
83
84 if (up->ier & UART_IER_THRI) {
85 up->ier &= ~UART_IER_THRI;
86 serial_out(up, UART_IER, up->ier);
87 }
88}
89
90static void serial_pxa_stop_rx(struct uart_port *port)
91{
92 struct uart_pxa_port *up = (struct uart_pxa_port *)port;
93
94 up->ier &= ~UART_IER_RLSI;
95 up->port.read_status_mask &= ~UART_LSR_DR;
96 serial_out(up, UART_IER, up->ier);
97}
98
99static inline void receive_chars(struct uart_pxa_port *up, int *status)
100{
101 unsigned int ch, flag;
102 int max_count = 256;
103
104 do {
105 /* work around Errata #20 according to
106 * Intel(R) PXA27x Processor Family
107 * Specification Update (May 2005)
108 *
109 * Step 2
110 * Disable the Reciever Time Out Interrupt via IER[RTOEI]
111 */
112 up->ier &= ~UART_IER_RTOIE;
113 serial_out(up, UART_IER, up->ier);
114
115 ch = serial_in(up, UART_RX);
116 flag = TTY_NORMAL;
117 up->port.icount.rx++;
118
119 if (unlikely(*status & (UART_LSR_BI | UART_LSR_PE |
120 UART_LSR_FE | UART_LSR_OE))) {
121 /*
122 * For statistics only
123 */
124 if (*status & UART_LSR_BI) {
125 *status &= ~(UART_LSR_FE | UART_LSR_PE);
126 up->port.icount.brk++;
127 /*
128 * We do the SysRQ and SAK checking
129 * here because otherwise the break
130 * may get masked by ignore_status_mask
131 * or read_status_mask.
132 */
133 if (uart_handle_break(&up->port))
134 goto ignore_char;
135 } else if (*status & UART_LSR_PE)
136 up->port.icount.parity++;
137 else if (*status & UART_LSR_FE)
138 up->port.icount.frame++;
139 if (*status & UART_LSR_OE)
140 up->port.icount.overrun++;
141
142 /*
143 * Mask off conditions which should be ignored.
144 */
145 *status &= up->port.read_status_mask;
146
147#ifdef CONFIG_SERIAL_PXA_CONSOLE
148 if (up->port.line == up->port.cons->index) {
149 /* Recover the break flag from console xmit */
150 *status |= up->lsr_break_flag;
151 up->lsr_break_flag = 0;
152 }
153#endif
154 if (*status & UART_LSR_BI) {
155 flag = TTY_BREAK;
156 } else if (*status & UART_LSR_PE)
157 flag = TTY_PARITY;
158 else if (*status & UART_LSR_FE)
159 flag = TTY_FRAME;
160 }
161
162 if (uart_handle_sysrq_char(&up->port, ch))
163 goto ignore_char;
164
165 uart_insert_char(&up->port, *status, UART_LSR_OE, ch, flag);
166
167 ignore_char:
168 *status = serial_in(up, UART_LSR);
169 } while ((*status & UART_LSR_DR) && (max_count-- > 0));
170 tty_flip_buffer_push(&up->port.state->port);
171
172 /* work around Errata #20 according to
173 * Intel(R) PXA27x Processor Family
174 * Specification Update (May 2005)
175 *
176 * Step 6:
177 * No more data in FIFO: Re-enable RTO interrupt via IER[RTOIE]
178 */
179 up->ier |= UART_IER_RTOIE;
180 serial_out(up, UART_IER, up->ier);
181}
182
183static void transmit_chars(struct uart_pxa_port *up)
184{
185 struct circ_buf *xmit = &up->port.state->xmit;
186 int count;
187
188 if (up->port.x_char) {
189 serial_out(up, UART_TX, up->port.x_char);
190 up->port.icount.tx++;
191 up->port.x_char = 0;
192 return;
193 }
194 if (uart_circ_empty(xmit) || uart_tx_stopped(&up->port)) {
195 serial_pxa_stop_tx(&up->port);
196 return;
197 }
198
199 count = up->port.fifosize / 2;
200 do {
201 serial_out(up, UART_TX, xmit->buf[xmit->tail]);
202 xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
203 up->port.icount.tx++;
204 if (uart_circ_empty(xmit))
205 break;
206 } while (--count > 0);
207
208 if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
209 uart_write_wakeup(&up->port);
210
211
212 if (uart_circ_empty(xmit))
213 serial_pxa_stop_tx(&up->port);
214}
215
216static void serial_pxa_start_tx(struct uart_port *port)
217{
218 struct uart_pxa_port *up = (struct uart_pxa_port *)port;
219
220 if (!(up->ier & UART_IER_THRI)) {
221 up->ier |= UART_IER_THRI;
222 serial_out(up, UART_IER, up->ier);
223 }
224}
225
226/* should hold up->port.lock */
227static inline void check_modem_status(struct uart_pxa_port *up)
228{
229 int status;
230
231 status = serial_in(up, UART_MSR);
232
233 if ((status & UART_MSR_ANY_DELTA) == 0)
234 return;
235
236 if (status & UART_MSR_TERI)
237 up->port.icount.rng++;
238 if (status & UART_MSR_DDSR)
239 up->port.icount.dsr++;
240 if (status & UART_MSR_DDCD)
241 uart_handle_dcd_change(&up->port, status & UART_MSR_DCD);
242 if (status & UART_MSR_DCTS)
243 uart_handle_cts_change(&up->port, status & UART_MSR_CTS);
244
245 wake_up_interruptible(&up->port.state->port.delta_msr_wait);
246}
247
248/*
249 * This handles the interrupt from one port.
250 */
251static inline irqreturn_t serial_pxa_irq(int irq, void *dev_id)
252{
253 struct uart_pxa_port *up = dev_id;
254 unsigned int iir, lsr;
255
256 iir = serial_in(up, UART_IIR);
257 if (iir & UART_IIR_NO_INT)
258 return IRQ_NONE;
259 spin_lock(&up->port.lock);
260 lsr = serial_in(up, UART_LSR);
261 if (lsr & UART_LSR_DR)
262 receive_chars(up, &lsr);
263 check_modem_status(up);
264 if (lsr & UART_LSR_THRE)
265 transmit_chars(up);
266 spin_unlock(&up->port.lock);
267 return IRQ_HANDLED;
268}
269
270static unsigned int serial_pxa_tx_empty(struct uart_port *port)
271{
272 struct uart_pxa_port *up = (struct uart_pxa_port *)port;
273 unsigned long flags;
274 unsigned int ret;
275
276 spin_lock_irqsave(&up->port.lock, flags);
277 ret = serial_in(up, UART_LSR) & UART_LSR_TEMT ? TIOCSER_TEMT : 0;
278 spin_unlock_irqrestore(&up->port.lock, flags);
279
280 return ret;
281}
282
283static unsigned int serial_pxa_get_mctrl(struct uart_port *port)
284{
285 struct uart_pxa_port *up = (struct uart_pxa_port *)port;
286 unsigned char status;
287 unsigned int ret;
288
289 status = serial_in(up, UART_MSR);
290
291 ret = 0;
292 if (status & UART_MSR_DCD)
293 ret |= TIOCM_CAR;
294 if (status & UART_MSR_RI)
295 ret |= TIOCM_RNG;
296 if (status & UART_MSR_DSR)
297 ret |= TIOCM_DSR;
298 if (status & UART_MSR_CTS)
299 ret |= TIOCM_CTS;
300 return ret;
301}
302
303static void serial_pxa_set_mctrl(struct uart_port *port, unsigned int mctrl)
304{
305 struct uart_pxa_port *up = (struct uart_pxa_port *)port;
306 unsigned char mcr = 0;
307
308 if (mctrl & TIOCM_RTS)
309 mcr |= UART_MCR_RTS;
310 if (mctrl & TIOCM_DTR)
311 mcr |= UART_MCR_DTR;
312 if (mctrl & TIOCM_OUT1)
313 mcr |= UART_MCR_OUT1;
314 if (mctrl & TIOCM_OUT2)
315 mcr |= UART_MCR_OUT2;
316 if (mctrl & TIOCM_LOOP)
317 mcr |= UART_MCR_LOOP;
318
319 mcr |= up->mcr;
320
321 serial_out(up, UART_MCR, mcr);
322}
323
324static void serial_pxa_break_ctl(struct uart_port *port, int break_state)
325{
326 struct uart_pxa_port *up = (struct uart_pxa_port *)port;
327 unsigned long flags;
328
329 spin_lock_irqsave(&up->port.lock, flags);
330 if (break_state == -1)
331 up->lcr |= UART_LCR_SBC;
332 else
333 up->lcr &= ~UART_LCR_SBC;
334 serial_out(up, UART_LCR, up->lcr);
335 spin_unlock_irqrestore(&up->port.lock, flags);
336}
337
338static int serial_pxa_startup(struct uart_port *port)
339{
340 struct uart_pxa_port *up = (struct uart_pxa_port *)port;
341 unsigned long flags;
342 int retval;
343
344 if (port->line == 3) /* HWUART */
345 up->mcr |= UART_MCR_AFE;
346 else
347 up->mcr = 0;
348
349 up->port.uartclk = clk_get_rate(up->clk);
350
351 /*
352 * Allocate the IRQ
353 */
354 retval = request_irq(up->port.irq, serial_pxa_irq, 0, up->name, up);
355 if (retval)
356 return retval;
357
358 /*
359 * Clear the FIFO buffers and disable them.
360 * (they will be reenabled in set_termios())
361 */
362 serial_out(up, UART_FCR, UART_FCR_ENABLE_FIFO);
363 serial_out(up, UART_FCR, UART_FCR_ENABLE_FIFO |
364 UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT);
365 serial_out(up, UART_FCR, 0);
366
367 /*
368 * Clear the interrupt registers.
369 */
370 (void) serial_in(up, UART_LSR);
371 (void) serial_in(up, UART_RX);
372 (void) serial_in(up, UART_IIR);
373 (void) serial_in(up, UART_MSR);
374
375 /*
376 * Now, initialize the UART
377 */
378 serial_out(up, UART_LCR, UART_LCR_WLEN8);
379
380 spin_lock_irqsave(&up->port.lock, flags);
381 up->port.mctrl |= TIOCM_OUT2;
382 serial_pxa_set_mctrl(&up->port, up->port.mctrl);
383 spin_unlock_irqrestore(&up->port.lock, flags);
384
385 /*
386 * Finally, enable interrupts. Note: Modem status interrupts
387 * are set via set_termios(), which will be occurring imminently
388 * anyway, so we don't enable them here.
389 */
390 up->ier = UART_IER_RLSI | UART_IER_RDI | UART_IER_RTOIE | UART_IER_UUE;
391 serial_out(up, UART_IER, up->ier);
392
393 /*
394 * And clear the interrupt registers again for luck.
395 */
396 (void) serial_in(up, UART_LSR);
397 (void) serial_in(up, UART_RX);
398 (void) serial_in(up, UART_IIR);
399 (void) serial_in(up, UART_MSR);
400
401 return 0;
402}
403
404static void serial_pxa_shutdown(struct uart_port *port)
405{
406 struct uart_pxa_port *up = (struct uart_pxa_port *)port;
407 unsigned long flags;
408
409 free_irq(up->port.irq, up);
410
411 /*
412 * Disable interrupts from this port
413 */
414 up->ier = 0;
415 serial_out(up, UART_IER, 0);
416
417 spin_lock_irqsave(&up->port.lock, flags);
418 up->port.mctrl &= ~TIOCM_OUT2;
419 serial_pxa_set_mctrl(&up->port, up->port.mctrl);
420 spin_unlock_irqrestore(&up->port.lock, flags);
421
422 /*
423 * Disable break condition and FIFOs
424 */
425 serial_out(up, UART_LCR, serial_in(up, UART_LCR) & ~UART_LCR_SBC);
426 serial_out(up, UART_FCR, UART_FCR_ENABLE_FIFO |
427 UART_FCR_CLEAR_RCVR |
428 UART_FCR_CLEAR_XMIT);
429 serial_out(up, UART_FCR, 0);
430}
431
432static void
433serial_pxa_set_termios(struct uart_port *port, struct ktermios *termios,
434 struct ktermios *old)
435{
436 struct uart_pxa_port *up = (struct uart_pxa_port *)port;
437 unsigned char cval, fcr = 0;
438 unsigned long flags;
439 unsigned int baud, quot;
440 unsigned int dll;
441
442 switch (termios->c_cflag & CSIZE) {
443 case CS5:
444 cval = UART_LCR_WLEN5;
445 break;
446 case CS6:
447 cval = UART_LCR_WLEN6;
448 break;
449 case CS7:
450 cval = UART_LCR_WLEN7;
451 break;
452 default:
453 case CS8:
454 cval = UART_LCR_WLEN8;
455 break;
456 }
457
458 if (termios->c_cflag & CSTOPB)
459 cval |= UART_LCR_STOP;
460 if (termios->c_cflag & PARENB)
461 cval |= UART_LCR_PARITY;
462 if (!(termios->c_cflag & PARODD))
463 cval |= UART_LCR_EPAR;
464
465 /*
466 * Ask the core to calculate the divisor for us.
467 */
468 baud = uart_get_baud_rate(port, termios, old, 0, port->uartclk/16);
469 quot = uart_get_divisor(port, baud);
470
471 if ((up->port.uartclk / quot) < (2400 * 16))
472 fcr = UART_FCR_ENABLE_FIFO | UART_FCR_PXAR1;
473 else if ((up->port.uartclk / quot) < (230400 * 16))
474 fcr = UART_FCR_ENABLE_FIFO | UART_FCR_PXAR8;
475 else
476 fcr = UART_FCR_ENABLE_FIFO | UART_FCR_PXAR32;
477
478 /*
479 * Ok, we're now changing the port state. Do it with
480 * interrupts disabled.
481 */
482 spin_lock_irqsave(&up->port.lock, flags);
483
484 /*
485 * Ensure the port will be enabled.
486 * This is required especially for serial console.
487 */
488 up->ier |= UART_IER_UUE;
489
490 /*
491 * Update the per-port timeout.
492 */
493 uart_update_timeout(port, termios->c_cflag, baud);
494
495 up->port.read_status_mask = UART_LSR_OE | UART_LSR_THRE | UART_LSR_DR;
496 if (termios->c_iflag & INPCK)
497 up->port.read_status_mask |= UART_LSR_FE | UART_LSR_PE;
498 if (termios->c_iflag & (IGNBRK | BRKINT | PARMRK))
499 up->port.read_status_mask |= UART_LSR_BI;
500
501 /*
502 * Characters to ignore
503 */
504 up->port.ignore_status_mask = 0;
505 if (termios->c_iflag & IGNPAR)
506 up->port.ignore_status_mask |= UART_LSR_PE | UART_LSR_FE;
507 if (termios->c_iflag & IGNBRK) {
508 up->port.ignore_status_mask |= UART_LSR_BI;
509 /*
510 * If we're ignoring parity and break indicators,
511 * ignore overruns too (for real raw support).
512 */
513 if (termios->c_iflag & IGNPAR)
514 up->port.ignore_status_mask |= UART_LSR_OE;
515 }
516
517 /*
518 * ignore all characters if CREAD is not set
519 */
520 if ((termios->c_cflag & CREAD) == 0)
521 up->port.ignore_status_mask |= UART_LSR_DR;
522
523 /*
524 * CTS flow control flag and modem status interrupts
525 */
526 up->ier &= ~UART_IER_MSI;
527 if (UART_ENABLE_MS(&up->port, termios->c_cflag))
528 up->ier |= UART_IER_MSI;
529
530 serial_out(up, UART_IER, up->ier);
531
532 if (termios->c_cflag & CRTSCTS)
533 up->mcr |= UART_MCR_AFE;
534 else
535 up->mcr &= ~UART_MCR_AFE;
536
537 serial_out(up, UART_LCR, cval | UART_LCR_DLAB); /* set DLAB */
538 serial_out(up, UART_DLL, quot & 0xff); /* LS of divisor */
539
540 /*
541 * work around Errata #75 according to Intel(R) PXA27x Processor Family
542 * Specification Update (Nov 2005)
543 */
544 dll = serial_in(up, UART_DLL);
545 WARN_ON(dll != (quot & 0xff));
546
547 serial_out(up, UART_DLM, quot >> 8); /* MS of divisor */
548 serial_out(up, UART_LCR, cval); /* reset DLAB */
549 up->lcr = cval; /* Save LCR */
550 serial_pxa_set_mctrl(&up->port, up->port.mctrl);
551 serial_out(up, UART_FCR, fcr);
552 spin_unlock_irqrestore(&up->port.lock, flags);
553}
554
555static void
556serial_pxa_pm(struct uart_port *port, unsigned int state,
557 unsigned int oldstate)
558{
559 struct uart_pxa_port *up = (struct uart_pxa_port *)port;
560
561 if (!state)
562 clk_prepare_enable(up->clk);
563 else
564 clk_disable_unprepare(up->clk);
565}
566
567static void serial_pxa_release_port(struct uart_port *port)
568{
569}
570
571static int serial_pxa_request_port(struct uart_port *port)
572{
573 return 0;
574}
575
576static void serial_pxa_config_port(struct uart_port *port, int flags)
577{
578 struct uart_pxa_port *up = (struct uart_pxa_port *)port;
579 up->port.type = PORT_PXA;
580}
581
582static int
583serial_pxa_verify_port(struct uart_port *port, struct serial_struct *ser)
584{
585 /* we don't want the core code to modify any port params */
586 return -EINVAL;
587}
588
589static const char *
590serial_pxa_type(struct uart_port *port)
591{
592 struct uart_pxa_port *up = (struct uart_pxa_port *)port;
593 return up->name;
594}
595
596static struct uart_pxa_port *serial_pxa_ports[4];
597static struct uart_driver serial_pxa_reg;
598
599#ifdef CONFIG_SERIAL_PXA_CONSOLE
600
601#define BOTH_EMPTY (UART_LSR_TEMT | UART_LSR_THRE)
602
603/*
604 * Wait for transmitter & holding register to empty
605 */
606static void wait_for_xmitr(struct uart_pxa_port *up)
607{
608 unsigned int status, tmout = 10000;
609
610 /* Wait up to 10ms for the character(s) to be sent. */
611 do {
612 status = serial_in(up, UART_LSR);
613
614 if (status & UART_LSR_BI)
615 up->lsr_break_flag = UART_LSR_BI;
616
617 if (--tmout == 0)
618 break;
619 udelay(1);
620 } while ((status & BOTH_EMPTY) != BOTH_EMPTY);
621
622 /* Wait up to 1s for flow control if necessary */
623 if (up->port.flags & UPF_CONS_FLOW) {
624 tmout = 1000000;
625 while (--tmout &&
626 ((serial_in(up, UART_MSR) & UART_MSR_CTS) == 0))
627 udelay(1);
628 }
629}
630
631static void serial_pxa_console_putchar(struct uart_port *port, int ch)
632{
633 struct uart_pxa_port *up = (struct uart_pxa_port *)port;
634
635 wait_for_xmitr(up);
636 serial_out(up, UART_TX, ch);
637}
638
639/*
640 * Print a string to the serial port trying not to disturb
641 * any possible real use of the port...
642 *
643 * The console_lock must be held when we get here.
644 */
645static void
646serial_pxa_console_write(struct console *co, const char *s, unsigned int count)
647{
648 struct uart_pxa_port *up = serial_pxa_ports[co->index];
649 unsigned int ier;
650 unsigned long flags;
651 int locked = 1;
652
653 clk_enable(up->clk);
654 local_irq_save(flags);
655 if (up->port.sysrq)
656 locked = 0;
657 else if (oops_in_progress)
658 locked = spin_trylock(&up->port.lock);
659 else
660 spin_lock(&up->port.lock);
661
662 /*
663 * First save the IER then disable the interrupts
664 */
665 ier = serial_in(up, UART_IER);
666 serial_out(up, UART_IER, UART_IER_UUE);
667
668 uart_console_write(&up->port, s, count, serial_pxa_console_putchar);
669
670 /*
671 * Finally, wait for transmitter to become empty
672 * and restore the IER
673 */
674 wait_for_xmitr(up);
675 serial_out(up, UART_IER, ier);
676
677 if (locked)
678 spin_unlock(&up->port.lock);
679 local_irq_restore(flags);
680 clk_disable(up->clk);
681
682}
683
684#ifdef CONFIG_CONSOLE_POLL
685/*
686 * Console polling routines for writing and reading from the uart while
687 * in an interrupt or debug context.
688 */
689
690static int serial_pxa_get_poll_char(struct uart_port *port)
691{
692 struct uart_pxa_port *up = (struct uart_pxa_port *)port;
693 unsigned char lsr = serial_in(up, UART_LSR);
694
695 while (!(lsr & UART_LSR_DR))
696 lsr = serial_in(up, UART_LSR);
697
698 return serial_in(up, UART_RX);
699}
700
701
702static void serial_pxa_put_poll_char(struct uart_port *port,
703 unsigned char c)
704{
705 unsigned int ier;
706 struct uart_pxa_port *up = (struct uart_pxa_port *)port;
707
708 /*
709 * First save the IER then disable the interrupts
710 */
711 ier = serial_in(up, UART_IER);
712 serial_out(up, UART_IER, UART_IER_UUE);
713
714 wait_for_xmitr(up);
715 /*
716 * Send the character out.
717 */
718 serial_out(up, UART_TX, c);
719
720 /*
721 * Finally, wait for transmitter to become empty
722 * and restore the IER
723 */
724 wait_for_xmitr(up);
725 serial_out(up, UART_IER, ier);
726}
727
728#endif /* CONFIG_CONSOLE_POLL */
729
730static int __init
731serial_pxa_console_setup(struct console *co, char *options)
732{
733 struct uart_pxa_port *up;
734 int baud = 9600;
735 int bits = 8;
736 int parity = 'n';
737 int flow = 'n';
738
739 if (co->index == -1 || co->index >= serial_pxa_reg.nr)
740 co->index = 0;
741 up = serial_pxa_ports[co->index];
742 if (!up)
743 return -ENODEV;
744
745 if (options)
746 uart_parse_options(options, &baud, &parity, &bits, &flow);
747
748 return uart_set_options(&up->port, co, baud, parity, bits, flow);
749}
750
751static struct console serial_pxa_console = {
752 .name = "ttyS",
753 .write = serial_pxa_console_write,
754 .device = uart_console_device,
755 .setup = serial_pxa_console_setup,
756 .flags = CON_PRINTBUFFER,
757 .index = -1,
758 .data = &serial_pxa_reg,
759};
760
761#define PXA_CONSOLE &serial_pxa_console
762#else
763#define PXA_CONSOLE NULL
764#endif
765
766static struct uart_ops serial_pxa_pops = {
767 .tx_empty = serial_pxa_tx_empty,
768 .set_mctrl = serial_pxa_set_mctrl,
769 .get_mctrl = serial_pxa_get_mctrl,
770 .stop_tx = serial_pxa_stop_tx,
771 .start_tx = serial_pxa_start_tx,
772 .stop_rx = serial_pxa_stop_rx,
773 .enable_ms = serial_pxa_enable_ms,
774 .break_ctl = serial_pxa_break_ctl,
775 .startup = serial_pxa_startup,
776 .shutdown = serial_pxa_shutdown,
777 .set_termios = serial_pxa_set_termios,
778 .pm = serial_pxa_pm,
779 .type = serial_pxa_type,
780 .release_port = serial_pxa_release_port,
781 .request_port = serial_pxa_request_port,
782 .config_port = serial_pxa_config_port,
783 .verify_port = serial_pxa_verify_port,
784#if defined(CONFIG_CONSOLE_POLL) && defined(CONFIG_SERIAL_PXA_CONSOLE)
785 .poll_get_char = serial_pxa_get_poll_char,
786 .poll_put_char = serial_pxa_put_poll_char,
787#endif
788};
789
790static struct uart_driver serial_pxa_reg = {
791 .owner = THIS_MODULE,
792 .driver_name = "PXA serial",
793 .dev_name = "ttyS",
794 .major = TTY_MAJOR,
795 .minor = 64,
796 .nr = 4,
797 .cons = PXA_CONSOLE,
798};
799
800#ifdef CONFIG_PM
801static int serial_pxa_suspend(struct device *dev)
802{
803 struct uart_pxa_port *sport = dev_get_drvdata(dev);
804
805 if (sport)
806 uart_suspend_port(&serial_pxa_reg, &sport->port);
807
808 return 0;
809}
810
811static int serial_pxa_resume(struct device *dev)
812{
813 struct uart_pxa_port *sport = dev_get_drvdata(dev);
814
815 if (sport)
816 uart_resume_port(&serial_pxa_reg, &sport->port);
817
818 return 0;
819}
820
821static const struct dev_pm_ops serial_pxa_pm_ops = {
822 .suspend = serial_pxa_suspend,
823 .resume = serial_pxa_resume,
824};
825#endif
826
827static const struct of_device_id serial_pxa_dt_ids[] = {
828 { .compatible = "mrvl,pxa-uart", },
829 { .compatible = "mrvl,mmp-uart", },
830 {}
831};
832MODULE_DEVICE_TABLE(of, serial_pxa_dt_ids);
833
834static int serial_pxa_probe_dt(struct platform_device *pdev,
835 struct uart_pxa_port *sport)
836{
837 struct device_node *np = pdev->dev.of_node;
838 int ret;
839
840 if (!np)
841 return 1;
842
843 ret = of_alias_get_id(np, "serial");
844 if (ret < 0) {
845 dev_err(&pdev->dev, "failed to get alias id, errno %d\n", ret);
846 return ret;
847 }
848 sport->port.line = ret;
849 return 0;
850}
851
852static int serial_pxa_probe(struct platform_device *dev)
853{
854 struct uart_pxa_port *sport;
855 struct resource *mmres, *irqres;
856 int ret;
857
858 mmres = platform_get_resource(dev, IORESOURCE_MEM, 0);
859 irqres = platform_get_resource(dev, IORESOURCE_IRQ, 0);
860 if (!mmres || !irqres)
861 return -ENODEV;
862
863 sport = kzalloc(sizeof(struct uart_pxa_port), GFP_KERNEL);
864 if (!sport)
865 return -ENOMEM;
866
867 sport->clk = clk_get(&dev->dev, NULL);
868 if (IS_ERR(sport->clk)) {
869 ret = PTR_ERR(sport->clk);
870 goto err_free;
871 }
872
873 ret = clk_prepare(sport->clk);
874 if (ret) {
875 clk_put(sport->clk);
876 goto err_free;
877 }
878
879 sport->port.type = PORT_PXA;
880 sport->port.iotype = UPIO_MEM;
881 sport->port.mapbase = mmres->start;
882 sport->port.irq = irqres->start;
883 sport->port.fifosize = 64;
884 sport->port.ops = &serial_pxa_pops;
885 sport->port.dev = &dev->dev;
886 sport->port.flags = UPF_IOREMAP | UPF_BOOT_AUTOCONF;
887 sport->port.uartclk = clk_get_rate(sport->clk);
888
889 ret = serial_pxa_probe_dt(dev, sport);
890 if (ret > 0)
891 sport->port.line = dev->id;
892 else if (ret < 0)
893 goto err_clk;
894 snprintf(sport->name, PXA_NAME_LEN - 1, "UART%d", sport->port.line + 1);
895
896 sport->port.membase = ioremap(mmres->start, resource_size(mmres));
897 if (!sport->port.membase) {
898 ret = -ENOMEM;
899 goto err_clk;
900 }
901
902 serial_pxa_ports[sport->port.line] = sport;
903
904 uart_add_one_port(&serial_pxa_reg, &sport->port);
905 platform_set_drvdata(dev, sport);
906
907 return 0;
908
909 err_clk:
910 clk_unprepare(sport->clk);
911 clk_put(sport->clk);
912 err_free:
913 kfree(sport);
914 return ret;
915}
916
917static int serial_pxa_remove(struct platform_device *dev)
918{
919 struct uart_pxa_port *sport = platform_get_drvdata(dev);
920
921 uart_remove_one_port(&serial_pxa_reg, &sport->port);
922
923 clk_unprepare(sport->clk);
924 clk_put(sport->clk);
925 kfree(sport);
926
927 return 0;
928}
929
930static struct platform_driver serial_pxa_driver = {
931 .probe = serial_pxa_probe,
932 .remove = serial_pxa_remove,
933
934 .driver = {
935 .name = "pxa2xx-uart",
936#ifdef CONFIG_PM
937 .pm = &serial_pxa_pm_ops,
938#endif
939 .of_match_table = serial_pxa_dt_ids,
940 },
941};
942
943static int __init serial_pxa_init(void)
944{
945 int ret;
946
947 ret = uart_register_driver(&serial_pxa_reg);
948 if (ret != 0)
949 return ret;
950
951 ret = platform_driver_register(&serial_pxa_driver);
952 if (ret != 0)
953 uart_unregister_driver(&serial_pxa_reg);
954
955 return ret;
956}
957
958static void __exit serial_pxa_exit(void)
959{
960 platform_driver_unregister(&serial_pxa_driver);
961 uart_unregister_driver(&serial_pxa_reg);
962}
963
964module_init(serial_pxa_init);
965module_exit(serial_pxa_exit);
966
967MODULE_LICENSE("GPL");
968MODULE_ALIAS("platform:pxa2xx-uart");